Dolphins, Whales and Porpoises

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Dolphins, Whales and Porpoises

• Mr. Adam Waterhouse

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Introduction

• The following presentation will introduce the
  variety of toothed whales that are found in our
  oceans
• I am Mr. Waterhouse.your host

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Topics of Discussion

• Toothed whales include dolphins, whales, and
  porpoises. The similarities and differences will
  be discussed and observed here.

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Taxonomy

• KingdomAnimalia
• PhylumCordata
• ClassMammalia
• OrderCetacea
• SuborderOdontocete (Toothed Whales)
• Mysticete (Baleen Whales)
• FamilyDelphinidae (Marine Dolphins)
• Phocoenidae (Porpoises)
• Iniidae (Boto)
• Pontoporiidae (Baiji and Franciscana)
• Plantanistidae (Indus Ganges River
  Dolphins)
• GenusThe first half of the scientific name.
• SpeciesThe second half of the scientific name.

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The DolphinsFamily - Delphinidae
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Dolphin Facts Skin and Color

• Dorsal side usually dark gray
• Ventral side usually white to pinkish
• Some exhibit spots on ventral side
• Counter shading protects dolphins from predators
  and helps in sneaking up on prey
• Skin has a rubbery feel.
• Skin made of a thin cornified layer and thick
  epidermis (humans are opposite)
• Blubber layer found below epidermis insulator

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Dorsal Fin
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Pectoral Fin
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Peduncle and Caudal Fin
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Dolphin FactsSkeleton

• Adapted for life at sea
• Bones do not have to carry a lot of weight
  (buoyancy), therefore are lighter than land
  mammals
• Flexible rib cage connected to the breastbone
  elastically. Allows the thorax to collapse
  without damage on deep dives.
• Hind limbs vestigial Front limbs flattened and
  shortened into pectoral fins (flippers)
• Neck is short due to fusion of some neck
  vertebrae.

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Dolphin Skeleton
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Dolphin Head

• Bottlenose dolphin has a well defined beak with
  fixed smile
• 18-26 pairs of sharp conical teeth in each jaw
• No chewing.no molars
• No milk teethpermanent
• Bulbous forehead is a large fatty body called the
  melon
• Melon is connected to a system of air sacs and
  aids in echolocation
• Crescent shaped single blow hole. Forceful
  exhale of blow followed by a rapid inhale. A lid
  covers the blow hole when under water.
• Below the blow hole is a system of air sacs which
  play a role in sound production. The air sac
  system is connected to the windpipe and the
  lungs.
• No connection of esophagus and windpipe.
• Tear ducts are present in corner of eye. Large
  quantities of tears help protect an lubricate the
  cornea.
• Small pinholes behind the eye are the ear
  openings.

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Dolphin Head
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Dolphin Melon
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Blowhole in Action
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Eye and Ear
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Pectoral Fin or Flipper

• Vertebrate front limb adapted into a swimming
  flipper
• Contain most of the same bones that are found in
  a human arm, but much shorter
• There are 5 digits and the carpals, ulna, radius,
  and humerus are all visible.
• Flippers act as stabilizers and as rudders, used
  to help steer.
• Can act as brakes
• Have many blood vessels close to the surface,
  playing a role in thermoregulation.
• When the body core heats up, more blood is pumped
  to flippers to help lose heat. If body
  temperature drops, blood flow to these vessels is
  limited.

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Labeled Dolphin Skeleton
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Tail Flukes

• Consists of 2 blades with a median notch between
  the blades
• Horizontal in the water
• Main source of propulsion
• Move in an up-down motion
• Connected to powerful muscles in the back and
  belly
• Just a few flicks of the tail can propel a
  dolphin clear of the water
• Cruising speed 12 km/hr 17km/hr
• When moving faster, they jump clear of the water
  (porpoising). This actually saves energy.
• Speeds of over 30km/hr have been recorded
• Dolphins riding the bow wave (front) of a boat
  can travel much faster as they are being pushed
  by the wave. Drafting boat can also help dolphin
  speeds.
• Tail Flukes also help with thermoregulation.

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Dorsal Fin

• Not all dolphins have a dorsal fin
• Killer whales have largest
• Bottlenose dolphin has a falcate (hook shaped)
  dorsal fin
• Acts to stabilize, similar to the lee-board on a
  boat
• Plays a role in thermoregulation

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A Leeboard
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Adapting to Life at Sea

• As a warm blooded mammal, dolphins keep their
  body temperature near 37 degrees C
• Water they live in can be 5-25 C
• Need ample insulation to retain heata thick
  blubber layer
• Role of tail, pectoral, and dorsal fin in
  thermoregulation
• Metabolic rate faster than land mammals

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Dolphin Senses

• Vision
• Hearing
• Touch
• Taste
• Smell

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Vison

• Vision is equally well above and below the water
  for most whales
• The eye is optimized for underwater vision
• Humans are extremely far sighted underwater, but
  the dolphin eye because the refractive power of
  the lens is better. The lens is found more
  forward and is spherical.
• The pupil has a lid (operculum) that slides down
  leaving a narrow slit. This helps with above
  water vision.
• The retina has both rods and cones, with similar
  functions as a human eye. Rods for low light,
  black and white vision. Cones for
  color..although dolphins do not have highly
  developed color vision. See red???
• Tapetum lucidum (behind retina) is presentused
  in low light conditions to maximize
  lightglowing!!

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Human Eye Anatomy
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Dolphin Eye (Fish Eye)
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Hearing

• External ear opening, behind eyes, with little or
  no function in hearing
• Auditory system of brain is highly developed,
  much larger than in humans
• Sound is conducted to the middle ear mainly via
  the blubber (an excellent sound conductor) and
  the lower jaw. Lower jaw is filled with fatty
  tissue which conducts sound. This tissue extends
  from the jaw to the inner ears.
• Experiments with sound absorbing hoods placed
  over the jaw, make hearing difficult.
• Middle ear cavities are suspended and surrounded
  by airaids in directional hearing

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Location of Middle and Inner Ear
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Touch

• Extremely tactile
• Most sensitive areas of touch include the area
  around the blowhole, eyes, and the upper and
  lower lips.
• The snout, melon, and lower jaw are less
  sensitive, while the skin on the back and tail
  are least sensitive

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That Feels Good!
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Taste

• Dolphins do swallow there food in large pieces,
  but they do taste
• Some dolphin species have taste buds on their
  tongue
• Preference to certain types of fish may be taste
  oriented

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Mouth
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Smell

• This one is easy..Toothed whales lack the
  sense of smell. It is possible that some baleen
  whales may have a slight sense of smell.
• What happened to the nostrils?

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Feeding

• Diet primarily consists of fish. Herring, small
  sharks, haddock, sole, mackerel, mullet, squid
  and even shrimp.
• Opportunistic feeders, going after the most
  abundant species available
• Killer whales will feed on mammals as well as
  fish

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Orca Killer Whale
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Water Availability

• Hydration does present a problem for
  dolphins..why?
• Surrounding sea water is too salty to drink
• Most water comes from the food they eat, or as a
  by-product of metabolizing fats and proteins
• Must conserve water Very efficient kidneys
  reabsorb water, releasing very concentrated urine.

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Feeding and Fishing Methods

• Dolphins do not chew, instead they usually
  swallow the fish whole, head first. Why?
• Head first keep the fins and spines of the fish
  folded back and will not hurt the throat of the
  dolphin
• Size of fish is determined by the size of the
  dolphin
• Echolocation (clicks) locates the food, and
  further loud sounds may stun the fish. This
  makes it much easier to catch
• Dolphins often hunt in groups, chasing and
  concentrating the fish.
• Some dolphins use their bow wave to push fish
  ashore, beaching themselves to eat.

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Bringing Fish to the Dinner Table
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Dolphin Behavior

• Why are people so intrigued by the behavior of
  dolphins?
• Lack of fear towards humans?
• Racing boats riding their bow wave?
• Saving the life of humans?
• Their never ending smile?
• Studying dolphins as a group is a good place to
  start the study of dolphin behavior.

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What is it about me???
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Group Composition

• The smallest social unit of dolphins is a pod
• Pods are fairly stable, but do change over time
• Type of pods include
• Mother-calf pairs
• Mixed-sex groups of subadults
• Single-sex groups of subadults
• Bands of females with their most recent offspring
• Adult male groups (usually pairs or trios)
• Social pods are the largest, while feeding pods
  are smaller
• Pod sizes vary and change

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What do you want to do? I dont know, what do
you want to do?
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Group Behavior

• Bond between mother and calf is strong. The two
  stay together from 3-6 years and maybe longer.
• Full grown dolphins will interact with their
  mother
• Calves that leave mom join subadult groups
• Subadult groups demonstrate many social
  behaviors Jumping, chasing, rubbing, stroking,
  pushing, and hetero and homosexual interactions.
• Adult female groups tend to travel with those in
  the same reproductive condition. Pregnant with
  pregnant young mothers with young mothers.
• Adult male groups rarely associate with
  subadults. They may consist of a group of two or
  three tightly boned males.
• These male groups can work together to separate a
  female from her group.kidnap her and keep her
  until mating occurs.
• Group synchronized movements are common..jumping
  and diving
• Dolphin groups are more active when their prey is
  active

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Video Clip

• http//www5.unitedstreaming.com/index.cfm
• Search Dolphin
• Select clips
• Page 1 click dolphin behavior.Stimulus
  response and intelligence

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Sleepingzzzzzzzzzzz

• Dolphins sleep on average about 30 of the day.
• Unlike humans, the brain of a dolphin sleeps one
  half at a time. They sleep with one eye open,
  monitoring their environment (unihemispheric
  sleeping)
• Probably no dreaming
• Dolphins can surface to breathe when sleeping,
  just as we roll over in our sleep.
• Dolphins swim slowly when asleep

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Sleeping Dolphin
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Playful Behavior

• Using the bow wave of a boat, whale, or mother is
  a fun way to travel fast and save energy
• Full breeching may be a signal to other dolphins
  and often times may be for fun.
• Porpoising is a way a saving energy when swimming
  fast.
• Trained dolphins can jump over 15 feet into the
  air
• Dolphins will play with inanimate toys without
  reward. They have been seen playing with
  turtles, gulls, and jelly fish.
• A game of fetch with leaves is a common way
  dolphins play with divers.

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Leaf Games
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Ring Toss!!!
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Care-Giving and Cooperative Behavior

• Dolphins have been observed helping sick or
  injured members of the group
• Dolphins have also been observed swimming away
  from dolphins entangled in fishing nets.
• Generally, dolphins will assist other dolphins
  when possible. Not likely that they will risk
  their own life to save another.
• When dolphins rest, usually a couple of dolphins
  take on the role of guards.

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Interactions With Other Species

• Bottlenose dolphins are often seen in the company
  of other dolphin species and larger whales.
• Small fish are often seen following dolphins,
  hoping to get a free meal. The remora is a good
  example.
• Bottlenose dolphins harass and even kill harbor
  porpoises, and harass spotted dolphins. They
  have been spotted helping the spotted dolphin by
  separating the females from the group.
• Assist humansin Maurentania dolphins are known
  to chase fish into the fishermens nets.
  Whyreward of easy fish to eat from the fishermen.

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Bottlenose and Spotted Dolphin
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Elian Gonzalez Cuban refugee saved
by dolphins while on an inner-tube
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A warm sendoff back to Cuba
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Reproduction and Calf Development
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Maturity

• Male bottlenose dolphins reach sexual maturity at
  age 13, while females are usually around 10.
• Females are considered mature when they ovulate
  regularly. Ovulation can begin as early as age
  5-7.
• Menopause is probable, since now female in her
  late thirties or more has successfully bred.
• Females are called cows, males are called bulls
  and babies are called calves.
• Birth is a year round event, but geography
  concentrates many births at a particular time.
  In Florida, spring and early summer are when most
  calves are born.
• Photoperiod (length of daylight), water
  temperature and food availability play a role in
  when child birth is optimal.
• Females do not usually get pregnant during
  lactation period.
• It takes about 6 months after weaning before
  females get pregnant again. Usually pregnant
  every 3-4 years.

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Reproductive Behavior

• Sexual interactions play an important role in
  dolphin social behavior.
• Male to female and male to male interactions
  occurs
• Dominant males will mount submissive males and
  females.
• Prior to actual mating there is a lot of physical
  contact between male and female. Fin to fin
  contact and snout to genital contact is common.
• Mild tooth raking is common on the skin and the
  actual mating process is very brief.
• Dolphins are polygamous animals. There are no
  permanent bonds between male and female. Usually
  a pair of males wanders the water in search of
  females to separate from the group and mate with.
  

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Female
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Male and Female Orca
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Dolphin Sex
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Pregnancy

• Gestation is about 12 months
• Young pregnant females (ages 5-10) have a low
  chance of successful childbirth
• Females 11-30 years old have most babies
• Survival rate of calves in the wild is only 80,
  not taking into account the calves that die
  before they are seen and the number of stillborn
  are unknown.
• Blood tests can reveal if a female is pregnant.
  Progesterone levels are measured. This is easy
  with captive dolphins, who dont even mind
  regular sonograms. Dolphins pick up sounds in
  the ultrasound range, but those used in sonograms
  are much higher in frequency and do not bother
  the dolphins.
• Pregnant and captive females are kept from
  performing high energy behaviors (jumps and slide
  outs). How much they want to interact with
  people is up to the dolphin.

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Pregnant Dolphin and a Sonogram
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Birth

• Normally a female gives birth to a singe calf at
  a time. Twins are rare and usually do not
  survive
• Usually calf is born tail first, although head
  first birth can be successful too
• Contractions of the uterus cause the female to
  flex her body. Milk is often ejected from the
  nipples during contractions. Nipples are found
  to the left and right of the genital opening.
• When the tail becomes visible, the mother
  continues to swim around. As delivery approaches
  the female will pick up speed and the baby is
  forcefully ejected, severing the umbilical cord.
  
• Newborn calf will instinctively go to the surface
  to breathe. There it is met by mom where he/she
  will swim in her wake. If the newborn does not
  go to the surface, the mother will push the baby
  up.
• Mother dolphins will push stillborn calves to the
  surface as well, and have been seen pushing it
  around for some time.

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Calf Development

• Newborns have soft and floppy dorsal fins and
  flukes. Why? They quickly straighten and
  stiffen.
• Fetal folds are present in newborns. These are
  light stripes that form due to the curled up
  nature of the fetus. As the calf ages the lines
  fade.
• Calves are usually 3-4 feet long and weigh about
  30kg.
• Cold water dolphin newborns are larger than warm
  water dolphins of the same species.
• Calf swims right away, usually in the mothers
  wake. Calf is usually above and behind the
  mother, known as the echelon position.
• Echolocation system not functional at birth, so
  they need to stay close to mom. Lots of touching
  mom with the flippers.
• Mothers milk is about 33 fat, allowing calves
  to double their length in one year and multiply
  its weight by 5 times. Weaning is usually
  between 18-20 months.

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Mom and Her Calf
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Calf Care

• Many different strategies when it comes to child
  rearing. Older and experienced mothers are
  better equipped to handle calves.
• Sometimes, another female in the group will help
  in taking care of the calf, occasionally taking
  the calf along, giving the mother a break.
• This female (and only one) is known as the aunt.
  She is not necessarily related to the mother, and
  is usually an experienced mother without a calf.\
• The males play no role in the care of the calf,
  even kept away.
• Nipples are located to the sides of the genital
  slit. When nursing, the calf leaves echelon
  position and goes toward the nipples. The female
  usually turns slightly on her side where the calf
  nudges the nipple.
• Mom will squirt milk into the calfs mouth to
  assist.
• As the calf ages, the number of nipple visits
  decline but the duration increases. The fatty
  milk helps to quickly build the blubber layer.
• As the calf ages it will leave mom now and then.
  Mom keeps an eye on the calf and retrieves it
  when it strays too far.
• When a calf misbehaves, the mom will discipline
  it by pushing against the bottom, pushing it or
  blasting it with loud sounds. Calf learns its
  place in the social group.
• Calves learn by imitation. They love to copy
  behaviors exhibited by mom.

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Nursing Spinner Dolphin
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Communication and Echolocation

• Dolphin vision is well developed, but their
  primary sense is hearing.
• Dolphins communicate mainly with sounds and they
  also get information from their environment by
  means of their echolocation.
• They produce a wide range of sounds, including
  whistles, pulsed sounds (squeaks, squawks, snorts
  and groans), and echolocation clicks.
• Dolphins also communicate with direct touch and
  possibly chemically, by tasting chemicals in the
  water.
• Non vocal sounds (tail slaps), jaw clapping and
  jumping are also used for communication. Jumping
  allows for both visual and acoustical
  communication.

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Types of Sounds

• Whistles
• Pulsed sounds
• Clicks (echolocation)
• LISTEN

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Communication Sounds

• The dolphin larynx differs from our own larynx.
  Shaped like a birds beak, it protrudes through
  the esophagus into the air passage in the head.
• The tip of the larynx has 4 flaps, which may
  vibrate but dont play a major role in sound
  production.
• The actual site of various sound production is
  not completely clear. In the dolphin head there
  are a system of air-filled sacs (nasal sacs)
  which do help with sound production. Air can be
  moved around these sacs without losing air to the
  water.

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Respiratory System
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The Use of Sounds

• Sounds are used to express excitement, agitation,
  anger, or warnings. Sounds are used to stay in
  contact with the groupI am here signal.
• Jaw clapping is clearly associated with
  aggression.
• Dolphins have a stereotyped whistle, unique for
  each individual The Signature whistle. It
  develops when the dolphins is only a few months
  old. Male dolphin signature whistles are similar
  to the mother and female whistles are quite
  different.

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Understanding Language

• Dolphins can learn to understand a variety of
  languages. English, whistled, sign, and symbolic
  languages are just a few.
• So far there is no evidence that dolphins
  communicate using a structured language like our
  own.
• The large brain of a dolphin appears to be
  primarily for processing sounds.

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Echolocation (Vision with Sound)

• Dolphins can produce clicks in rapid succession.
  These clicks are short high frequency sounds, and
  vary from species to species. Bats use the same
  type of bio-sonar to see with sound.
• The clicks are emitted in series, called click
  trains. The clicks are spaced 20-200msec apart.
  The human ear can hear this as a rasping or
  buzzing sound. As a dolphin approaches its
  target the frequency of clicks increases (like
  focusing).

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Echolocation
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Echolocation Application

• Echolocation is used primarily to locate food
  (fish) and then for orientation.
• The clicks are produced in the air passages in
  the head, passes through the nasal sacs, which
  are connected to the melon. The large fatty
  melon bends the sound and focuses it into a
  narrow beam of sound, just like a lens can do
  with light.
• The melon is an acoustical lens.
• In 15 C sea water, sound travels almost 5 times
  faster than in air. As a sound wave meets an
  object, part of the wave is reflected back to the
  sender at the same speed.
• Since only part of the wave is returned, it is
  not as loud. The lower jaw picks up this sound
  and its fat transmits the sound to the middle
  then inner ear. From here, nerves send signals
  to the brain for interpretation.

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Echolocation Continued..

• From an echo, the dolphin can determine the
  following Distance, shape, texture, direction,
  and size.
• More clicks are sent to the object to further
  analyze what it is.
• A dolphin with its eyes covered can detect a
  7.62 cm metal disc from a distance of 113 meters.

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Bye Bye!!!!
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Atlantic Hump-Backed Dolphin
Scientific Name Sousa teuszii Other Names
Atlantic Humpback Dolphin, Cameroon Length
6.5-8.3 ft. (2-2.5 m.) Weight 220-330 lbs.
(100-150 kg.) Teeth 100-126
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Bottlenose Dolphin

• Scientific Name Tursiops truncatus Other Names
  Bottle-nosed Dolphin, Cowfish Length 6.3-12.8
  ft. (1.9-3.9 m.) Weight 330-1440 lbs. (150-650
  kg.) Teeth 74-100

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Black Dolphin

• Scientific Name Cephalorhynchus eutropia Other
  Names Chilean Dolphin Length 4-5.8 ft.
  (1.2-1.7 m.) Weight 65-145 lbs. (30-65 kg.)
  Teeth 112-136

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Dusky Dolphin

• Scientific Name Lagenorhynchus obscurus Other
  Names Fitzroy's Dolphin Length 5.3-7 ft.
  (1.6-2.1 m.) Weight 110-200 lbs. (50-90 kg.)
  Teeth 94-144

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False Killer Whale

• Scientific Name Pseudorca crassidens Other
  Names False Pilot Whale Length 14-19.8 ft.
  (4.3-6 m.) Weight 1.1-2.2 tons Teeth 32-44

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Killer Whale

• Scientific Name Orcinus orca Other Names
  Grampus, Great Killer Whale Length 18-32.3 ft.
  (5.5-9.8 m.) Weight 2.6-9 tons Teeth 40-52

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Striped Dolphin

• Scientific Name Stenella coeruleoalba Other
  Names Whitebelly dolphin, Blue-white dolphin,
  Gray's dolphin Length 6-8.3 ft. (1.8-2.5 m.)
  Weight 200-330 lbs. (90-150 kg.) Teeth
  156-216

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White-Beaked Dolphin

• Scientific Name Lagenorhynchus albirostris
  Length 8.3-9.3 ft. (2.5-2.8 m.) Weight
  395-605 lbs. (180-275 kg.) Teeth 88-112

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Irrawaddy Dolphin

• Scientific Name Orcaella brevirostris Other
  Names Snubfin Dolphin Length 7-8.5 ft.
  (2.1-2.6 m.) Weight 200-330 lbs. (90-150 kg.)
  Teeth 62-76

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Atlantic Spotted Dolphin

• (Stenella frontalis)Length--6-8 ft.Weight--250
  lbs.Lifespan--45 yearsSexual Maturity--Males-12
  years, Females-9 yearsPregnancy--11-12 months,
  every 2-4 years

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Final Activity

• United streaming..
• http//www5.unitedstreaming.com/index.cfm
• In the Company of Whales - Film

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